In a motor vehicle having an electric drive, the available drive torque that can be provided by the electrical machine depends on a large number of influencing variables. For example, the drive power or the traction force on the vehicle wheel may be derated, that is to say throttled, for thermal reasons as a function of the external temperature, the driving profile (power requirement over time) and as a function of the design/dimensioning of the cooling measures in the motor vehicle or on the drive component. Throttling of this kind is due, for example, to component protection (avoiding overheating). This applies, in particular, for electrical power output by the battery and the power conversion in the drive system (power electronics and electrical machine). In addition, the performance of the traction battery depends on further parameters, for example the state of charge, age or temperature.
An, in particular, electric drive unit is provided for generating a drive torque in a motor vehicle of this generic type. The motor vehicle has an accelerator pedal which is subjected to the action of a restoring force, it being possible for the accelerator pedal to be adjusted by an actuating movement in order to prespecify a setpoint torque. A control device can actuate the drive unit, in order to generate a drive torque, on the basis of a setpoint torque set by the driver.
The drive torque which is currently available during driving can vary as a function of specific driving situations. In specific driving situations, for example when executing an overtaking maneuver, the electrical machine can provide a relatively high drive power for accelerating and maintaining a specific vehicle speed. However, during a driving situation such as this, the currently available drive torque can drop on account of the above-mentioned parameters, and therefore the high drive power can be provided only briefly.
Against this background, information about the drive capability of the motor vehicle is of great importance to the driver.